1. Field of the Invention
This invention relates to compounds which are useful additives for lubricating oils. In particular, this invention is directed toward overbased derivatives of ortho-carboxy phenylphenone. The overbased derivatives of ortho-carboxy phenylphenones are useful lubricating oil additives which provide detergency while additionally providing an alkaline reserve for the lubricating oil. An alkalinity reserve is necessary in the lubricating oil in order that acids generated during engine operation may be neutralized. Without this alkalinity reserve, the acids generated result in unwanted corrosion in the engine.
2. Background of the Invention
U.S. Pat. No. 3,526,661 discloses that alkaryl keto acids amidated by reaction with aliphatic polyamines are useful sludge dispersancy and detergency additives for lubricating oils.
U.S. Pat. No. 4,379,092 discloses a process for the preparation of ortho-carboxy phenylphenones. These compounds are taught as intermediates in the synthesis of anthraquinones, which themselves are taught as being used for dyestuffs, paper pulp industries and for the manufacture of hydrogen peroxide.
Great Britian Application No. 1,450,733 discloses ortho-carboxy phenylphenones as useful starting materials for dyes and insecticides.
Other alkyl-substituted ortho-carboxy phenylphenones are disclosed in CA No. 80:47709(e); CA No. 83:146931(q); CA No. 84:179413(w); CA No. 94:15446(q); and U.S. Pat. Nos. 3,880,892 and 3,816,124. Salts of lower alkyl-substituted ortho-carboxy phenylphenones are disclosed in CA No. 82:172012(q). However, there is no teaching in these references, or apparently elsewhere, to prepare overbased derivatives of ortho-carboxy phenylphenones or that these overbased derivatives of ortho-carboxy phenylphenones would be useful additives for lubricating oils.